Caisteal Grugaig is an Iron Age broch standing on a small rocky knoll on a grassy slope. The 'Glenelg Brochs' of Dun Telve and Dun Troddan are a few miles to the south. Caisteal Grugaig should not be confused with the 'semi-broch' known as Dun Grugaig which is also near Glenelg.
The broch has an external diameter of around 16.5 metres and an internal diameter of around 9.6 metres. The broch was built on uneven ground, so the natural floor of the broch has a slope. The entrance passage is on the northeast side and has a massive triangular lintel over the doorway. There is an elongated guard cell on the left side of the entrance passage.
The interior of the broch has two intramural rooms at ground level, one of which is a small, oval cell. The other is a long mural cell, or length of ground gallery, which has a blocked doorway. The sides of an upper room are apparent above the entrance passage. Also inside the broch is a doorway to the mural stair. The five steps of the stair lead up to a long landing which leads to the beginning of a second flight of stairs.
References:The Château de Foix dominates the town of Foix. An important tourist site, it is known as a centre of the Cathars. Built on an older 7th-century fortification, the castle is known from 987. In 1002, it was mentioned in the will of Roger I, Count of Carcassonne, who bequeathed the fortress to his youngest child, Bernard. In effect, the family ruling over the region were installed here which allowed them to control access to the upper Ariège valley and to keep surveillance from this strategic point over the lower land, protected behind impregnable walls.
In 1034, the castle became capital of the County of Foix and played a decisive role in medieval military history. During the two following centuries, the castle was home to Counts with shining personalities who became the soul of the Occitan resistance during the crusade against the Albigensians.